Method and apparatus for multiplexing data and control information in wireless communication systems based on frequency division multiple access

ABSTRACT

A signal reception apparatus comprises a receiver configured to receive a symbol block within a symbol period of a wireless communication network and a control information demodulator/decoder configured for demultiplexing control information and data information from the received symbol block.

PRIORITY

This application is a divisional of U.S. patent application Ser. No.12/661,001, filed on Mar. 8, 2010, now U.S. Pat. No. 7,929,590, which isa continuation of U.S. patent application Ser. No. 12/481,337, filed onJun. 9, 2009, now U.S. Pat. No. 7,697,631, which is a divisional of U.S.patent application Ser. No. 11/416,393, filed on May 3, 2006, now U.S.Pat. No. 7,613,245, which claims the benefit under 35 U.S.C. §119(a) ofa Korean Patent Application filed in the Korean Industrial PropertyOffice on May 3, 2005 and assigned Serial No. 2005-37294, the entiredisclosures of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a wireless communication system basedon frequency division multiple access. More particularly, the presentinvention relates to a method and apparatus for multiplexing andtransmitting data and control information in a wireless communicationsystem based on frequency division multiple access.

2. Description of the Related Art

Recent developments in broadcasting and mobile communication systemstechnology has led to the wide use of an Orthogonal Frequency DivisionMultiplexing (OFDM) transmission scheme. The OFDM scheme eliminates theinterference between multi-path signals, which is frequently found inwireless communication channels. Also, the OFDM scheme guarantees theorthogonality between multiple access users and facilitates an efficientuse of resources. Therefore, the OFDM scheme is available for high speeddata transmission and broadband systems more than the conventional CodeDivision Multiple Access (CDMA) scheme. However, the OFDM scheme is amulti-carrier transmission scheme, in which transmission data isdistributed to multiple sub-carriers and is then transmitted inparallel. This causes the OFDM scheme to increase the Peak-to-AveragePower Ratio (PAPR) of the transmission signals.

A large PAPR causes distortion of output signals in a Radio Frequency(RF) power amplifier of a transmitter. Therefore, in order to solve sucha problem, the transmitter requires power back-off to reduce the inputpower to the amplifier. Therefore, when the OFDM scheme is applied tothe uplink of a mobile communication system, a terminal must perform thepower back-off for the transmission signals, which results in thereduction of the cell coverage.

Interleaved Frequency Division Multiple Access (IFDMA) is being activelyresearched as a solution to solve the PAPR problem of the OFDMtechnology. The IFDMA guarantees the orthogonality between the multipleaccess users like the OFDM and is a technology based on a singlesub-carrier, which shows a very low PAPR of transmission signals.Applying the IFDMA to a mobile communication system reduces the problemof cell coverage reduction due to the PAPR increase.

FIG. 1 illustrates a structure of a typical IFDMA transmitter.

Although the structure shown in FIG. 1 uses a Fast Fourier Transform(FFT) unit 104 and an Inverse Fast Fourier Transform (IFFT) unit 106,exemplary embodiments of the present invention are not limited to theshown structure and can be implemented by additional structures. Theimplementation that uses the FFT unit 104 and the IFFT unit 106 isadvantageous because it facilitates an easy change of IFDMA systemparameters without a high hardware complexity.

The OFDM and the IFDMA may have the following differences in the aspectof transmitter structure. In addition to the IFFT unit 106 which is usedfor multi-carrier transmission in the OFDM transmitter, the IFDMAtransmitter includes the FFT unit 104 located before the IFFT unit 106.Therefore, the transmission modulation (TX) symbols 100 in FIG. 1 areinput to the FFT unit 104 block by block, each of which includes Mnumber of transmission modulation symbols. The block is referred to as“symbol block,” and the period at which the symbol block is input to theFFT unit is referred to as “symbol block period.” The signals outputfrom the FFT unit 104 are input to the IFFT unit 106 at equal intervals,so that the IFDMA transmission signal elements are transmitted in thefrequency domain by sub-carriers of equal intervals. In this process, itis usual for the input/output size N of the IFFT unit 106 to have alarger value than that of the input/output size M of the FFT unit 104.In the OFDM transmitter, the transmission symbol blocks 100 are directlyinput to the IFFT unit 106 without passing through the FFT unit 104 andare then transmitted by multiple sub-carriers, thereby generating a PAPRwith a large value.

In the IFDMA transmitter, the transmission symbols are pre-processed bythe FFT unit 104 before being processed by the IFFT unit 106. Thisoccurs even though the transmission symbols are finally processed by theIFFT unit 106 before being transmitted by multiple carriers. Thepre-processing of the transmission symbols makes it possible, due to thecounterbalancing between the FFT unit 104 and the IFFT unit 106, to havean effect similar to that which occurs when the output signals of theIFFT unit 106 are transmitted by a single sub-carrier, thereby achievinga low PAPR. Finally, the outputs of the IFFT unit 106 are converted to aserial stream by a Parallel-to-Serial Converter (PSC) 102. Before theserial stream is then transmitted, a Cyclic Prefix (CP) or guardinterval is attached to the serial stream as it is in the OFDM system,to prevent interference between multi-path channel signal elements.

FIG. 2 illustrates a structure of a transmitter based on a LocalizedFrequency Division Multiple Access (LFDMA) technique, which is similarto the IFDMA technique. The LFDMA technique also guarantees theorthogonality between multiple access users, is based on single carriertransmission, and can achieve a PAPR lower than that of the OFDM. Asillustrated in FIGS. 1 and 2, the difference between the LFDMA and theIFDMA in the view of transmitter structure is that the outputs of theFFT unit 204 turn into inputs to the IFFT unit 206, which havesequential indexes following the last index of the FFT unit 204. In thefrequency domain, the LFDMA signals occupy the band constituted byadjacent sub-carriers used when the outputs of the FFT unit 204 aremapped into the inputs of the IFFT unit 206. In other words, in thefrequency domain, the IFDMA signals occupy the sub-carrier bands(sub-bands) distributed at an equal interval, and the LFDMA signalsoccupy the sub-band constituted by adjacent sub-carriers.

In order to apply the IFDMA and LFDMA based systems to a broadcasting ormobile communication system, it is necessary to transmit data as well ascontrol information and a pilot signal for demodulating and decoding thedata in a receiver. The pilot signal has a guaranteed pattern between atransmitter and a receiver. Therefore, when a received signal has adistortion due to a wireless fading channel, the receiver can estimateand eliminate, based on the pilot signal, the distortion in the receivedsignal due to the wireless fading channel. The control informationincludes a modulation scheme applied to the transmitted data, a channelcoding scheme, a data block size, and Hybrid Automatic Repeat Request(HARD)-related information such as a serve packet ID. By receiving thecontrol information, the receiver can understand the information appliedto the transmitted data to perform various operations includingdemodulation and decoding of the received data.

According to the CDMA technique widely applied to current mobilecommunication systems, the data, control information, and pilot signalare transmitted by using different channelization codes. This allows thereceiver to separate and detect the signals without interference.According to the OFDM technique, the data, control information, andpilot signal are transmitted by different sub-carriers or after beingtemporally divided.

Since the control information is not a large quantity of informationcapable of totally occupying one time slot, application of the timedivision-based multiplexing scheme may result in an unnecessary waste ofresources. When the control information is transmitted by a separatesub-carrier different from that which carries the data as it does in theOFDM scheme, it is problematic in that the transmitted signal has anincreased PAPR.

Accordingly, there is a need for an improved method and apparatus formultiplexing data and control information to lower a PAPR of atransmitted signal and to facilitate resource efficiency in an IFDMA orLFDMA-based communication system.

SUMMARY OF THE INVENTION

An aspect of exemplary embodiments of the present invention is toaddress at least the above problems and/or disadvantages and to provideat least the advantages described below. Accordingly, an aspect ofexemplary embodiments of the present invention is to provide a methodand an apparatus for multiplexing data and control information to lowera PAPR of a transmitted signal and to facilitate the efficient use ofresources in an IFDMA or LFDMA-based communication system.

It is another object of an exemplary embodiment of the present inventionto provide a method and an apparatus for multiplexing data and controlinformation at an FFT input side within one FFT block period in an IFDMAor LFDMA-based communication system.

It is also another object of an exemplary embodiment of the presentinvention to provide a method and an apparatus for multiplexing data bydistributing control information in each symbol block period within aTransmission Time Interval (TTI) in an IFDMA or LFDMA-basedcommunication system.

In order to accomplish this object, an apparatus for transmitting datain a frequency division multiple access based communication system isprovided. The apparatus includes a symbol block generator, a FastFourier Transform (FFT) unit, and an Inverse Fast Fourier Transform(IFFT) unit. The symbol block generator generates a symbol block in apredetermined symbol block period within one Transmission Time Interval(TTI) when control information to be transmitted exists in the TTI.Also, the symbol block includes the control information and data to betransmitted and the TTI includes multiple symbol block periods. A FastFourier Transform (FFT) unit performs FFT on the symbol block and anInverse Fast Fourier Transform (IFFT) unit performs IFFT on signalsoutput from the FFT unit and then transmits the signals.

In accordance with another aspect of an exemplary embodiment of thepresent invention, a method for transmitting data in a frequencydivision multiple access based communication system is provided. Asymbol block is generated in a predetermined symbol block period withinone Transmission Time Interval (TTI) when control information to betransmitted exists in the TTI. The symbol block includes the controlinformation and data to be transmitted and the TTI includes multiplesymbol block periods. Fast Fourier Transform (FFT) is performed on thesymbol block, Inverse Fast Fourier Transform (IFFT) is performed on theFFTed signals, and then the IFFTed signals are transmitted.

In accordance with another aspect of an exemplary embodiment of thepresent invention, an apparatus for receiving data in a frequencydivision multiple access based communication system is provided. Theapparatus includes a Fast Fourier Transform (FFT) unit, an Inverse FastFourier Transform (IFFT), a control information demodulator/decoder, anda data demodulator/decoder. The FFT unit receives signals receivedduring one symbol block period and performs FFT on the signals. The unitperforms IFFT on the signals output from the FFT unit, thereby restoringsymbol blocks. When the symbol block period is a predetermined symbolblock period in which data and control information are multiplexed, thecontrol information demodulator/decoder, receives modulation symbolscorresponding to predetermined IFFT output indexes from among the symbolblocks and demodulates and decodes the modulation symbols, therebyoutputting control information. The data demodulator/decoder receivesmodulation symbols corresponding to the other IFFT output indexes exceptfor indexes corresponding to the control information from among thesymbol blocks by using the control information, demodulates and decodesthe received modulation symbols, and then outputs the data.

According to another aspect of an exemplary embodiment of the presentinvention, a method for receiving data in a frequency division multipleaccess based communication system is provided. The method includes thesteps of: receiving signals received during one symbol block period andperforming Fast Fourier Transform (FFT) on the signals by an FFT unit;restoring symbol blocks from the FFTed signals by an Inverse FastFourier Transform (IFFT) unit; when the symbol block period is apredetermined symbol block period in which data and control informationare multiplexed, receiving modulation symbols corresponding topredetermined IFFT output indexes from among the symbol blocks from theIFFT unit and demodulating and decoding the modulation symbols, therebyoutputting control information; and receiving modulation symbolscorresponding to the other IFFT output indexes except for indexescorresponding to the control information from among the symbol blocksfrom the IFFT unit by using the control information, demodulating anddecoding the received modulation symbols, and then outputting the data.

Other objects, advantages, and salient features of the invention willbecome apparent to those skilled in the art from the following detaileddescription, which, taken in conjunction with the annexed drawings,discloses exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other exemplary objects, features and advantages ofcertain exemplary embodiments of the present invention will be moreapparent from the following detailed description taken in conjunctionwith the accompanying drawings, in which:

FIG. 1 illustrates a structure of a conventional IFDMA transmitter;

FIG. 2 illustrates a structure of a conventional LFDMA transmitter;

FIG. 3 illustrates an apparatus for multiplexing and transmitting data,control information, and a pilot signal according to a first exemplaryembodiment of the present invention;

FIG. 4 illustrates the FFT mapping in the symbol block period in whichthe control information and the data are multiplexed according to thefirst exemplary embodiment of the present invention;

FIG. 5 illustrates a structure of a receiver according to the firstexemplary embodiment of the present invention;

FIG. 6 illustrates a method for multiplexing control information anddata according to a second exemplary embodiment of the presentinvention;

FIG. 7 illustrates a structure for mapping IFFT outputs to the controlinformation demodulator/decoder and the data demodulator/decoder in thereceiver according to the first or second exemplary embodiment of thepresent invention;

FIG. 8 is a flowchart for illustrating the operation of the receiveraccording to a first exemplary embodiment of the present invention; and

FIG. 9 is a flowchart showing an operation of a transmitter according toan exemplary embodiment of the present invention.

Throughout the drawings, the same drawing reference numerals will beunderstood to refer to the same elements, features, and structures.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The matters defined in the description such as a detailed constructionand elements are provided to assist in a comprehensive understanding ofthe embodiments of the invention. Accordingly, those of ordinary skillin the art will recognize that various changes and modifications of theembodiments described herein can be made without departing from thescope and spirit of the invention. Also, descriptions of well-knownfunctions and constructions are omitted for clarity and conciseness.

An exemplary embodiment of the present invention proposes a method ofmultiplexing data and control information in at least one symbol blockfrom among multiple symbol blocks included in one TTI and simultaneouslytransmitting the multiplexed data and control information. The method ofmultiplexing and simultaneous transmission can achieve a lower PAPR andresults in a more efficient use of resources compared to the existingmethods. The control information includes a modulation scheme applied totransmission data, a channel coding scheme, a data block size, and aHybrid Automatic Repeat Request (HARQ)-related information such as asub-packet ID. This is included together with control information, suchas Channel Quality Indicator (CQI) or ACK/NACK, when the controlinformation is necessary.

FIG. 3 illustrates an apparatus for multiplexing and transmitting data,control information, and a pilot signal according to a first exemplaryembodiment of the present invention.

As shown in FIG. 3, a symbol block generator 304 of a transmittergenerates a symbol block by multiplexing data, control information, orpilot signals to be transmitted for each symbol block period. Theexemplary embodiment of FIG. 3 illustrates one Transmission TimeInterval (TTI) which includes eight symbol block periods.

The symbol block generator 304 determines whether control informationexists within the current TTI 300. When control information existswithin the current TTI 300, the symbol block generator 304 generates asymbol block including the control information and data in apredetermined symbol block period 302 within the TTI 300. The symbolblock generator 304 generates symbol blocks which include data or apilot signal without control information in other symbol block periods.Each symbol block includes M number of symbols, which are mapped to Mnumber of inputs of the FFT unit 310.

In FIG. 3, the IFDMA or LFDMA transmission technique is to transmit theoutput signals of the FFT unit 310 by multi-carriers by using the IFFTunit 314. Therefore, N number of outputs from the IFFT unit 314 areconverted to a serial stream by the PSC 102 as shown in FIG. 1, which isthen transmitted with a CP attached thereto. At this time, each periodin which the N outputs are generated corresponds to the symbol blockperiod.

Therefore, each of the eight symbol blocks in the TTI 300 is input tothe FFT unit 310 at a corresponding symbol block period. Each of thesymbol blocks is an FFT input block input through all input taps of theFFT unit 310 and has the same size as the tap size M of the FFT unit310. Further, the M outputs of the FFT unit 310 are mapped to the inputsof the IFFT unit 314 according to the mapping rule corresponding to theIFDMA or LFDMA technique to be applied which is similar to thetechniques applied FIGS. 1 and 2. Finally, the outputs of the IFFT unit314 are converted to a serial stream, which is then transmitted togetherwith a CP attached thereto.

FIG. 9 is a flowchart illustrating an operation of a transmitteraccording to an exemplary embodiment of the present invention.

In step 900, the transmitter generates frames in TTI, that is,transmission data, by multiplexing data, control information, and pilotsignals to be transmitted. When there is control information to betransmitted during one TTI, the transmitter inserts the controlinformation into a symbol block predetermined within the TTI, andinserts data into a remaining portion of the symbol block. The pilotsignal is included in and transmitted by one symbol block, and the datais included in a portion of the symbol block including the controlsignal and other symbol blocks except for the symbol block including thepilot signal. In step 902, the transmitter performs FFT on a symbolblock of a corresponding period at each symbol block period.

In step 904, the outputs of the FFT unit are mapped to the inputs of theIFFT unit according to the mapping rule corresponding to the appliedIFDMA or LFDMA technique to be applied, and IFFT is then performed. Instep 906, the transmitter attaches a CP to the output of the IFFT unitand then transmits it.

As described above, the method proposed by the first exemplaryembodiment of the present invention is to multiplex the data 306 and thecontrol information 304 at the FFT input side during one symbol blockperiod. The pilot signal 308 is transmitted during one entire symbolblock period. This method of transmission is different from that of thedata 306 and the control information 304. In the case of IFDMA or LFDMAtransmission, when the pilot signal 308 is multiplexed together withdata within the same symbol block period, it is difficult to performchannel estimation and normally demodulate the received data and controlinformation. However, as noted from the following description regardingthe operation of a receiver, even when the control information 304 ismultiplexed together with the data 306 within one symbol block period,it is possible to demodulate and decode the received data 306 and thecontrol information 304.

The method for multiplexing data 306, the control information 304, andthe pilot signal 308 is applicable even to an IFDMA or LFDMA transmitterwhich is not based on the FFT and IFFT.

Multiplexing the data and control information in one IFDMA symbol streamas shown in FIG. 3 makes it possible to obtain a lower PAPR, incomparison with the case data and control information which are dividedin the frequency domain and are then transmitted according to the IFDMAor LFDMA scheme by using different sub-carrier bands as in an OFDMsystem. Further, the method as shown in FIG. 3 facilitates a moreefficient use of resources, in comparison with the case of temporallymultiplexing the data and the control information and then transmittingthem in different symbol block periods by IFDMA or LFDMA. This resultsfrom the fact that the control information usually has a small volume,and allocation of one symbol block period to the transmission of thecontrol information would result in allocation of an unnecessarily largequantity of resources to the transmission of the control information andcause a reduction of many resources which could otherwise be used forthe data transmission. This problem becomes more severe when it isnecessary to transmit a large quantity of data at a high data rate.

Hereinafter, a description will be given regarding the frame format of atransmission IFDMA or LFDMA signal for normal demodulation and decodingof data by a receiver when the data and control information aremultiplexed as described above. According to the quantity of data to betransmitted or the condition of a transmitted radio channel, differentmodulation schemes and coding schemes may be applied to the datatransmission. When the HARQ technique is applied, different HARQ controlinformation may be transmitted according to the retransmissionsituations. Therefore, normal demodulation of data is possible only whenthe receiver has recognized the control information by demodulating anddecoding the control information.

The transmission format of the control information should be defined tobe fixed to a specific transmission format or as one format used betweenthe transmitter and the receiver at the time of radio link setup tofacilitate normal demodulation of the control information by the user.The receiver can normally demodulate and decode the control informationwhen the control information is mapped and transmitted with an alwaysfixed modulation scheme and channel coding scheme, fixed number ofcontrol information bits, and fixed time slots and FFT inputs. Forexample, the exemplary embodiment of FIG. 3 illustrates the controlinformation convolutionally encoded with a coding rate of ⅓ and thentransmitted according to the QPSK modulation scheme, and includes Lnumber of modulation symbols. The L modulation symbols are transmittedafter being applied to the FFT inputs with input indexes of 0˜(L−1) inthe second symbol block period within the TTI. Then, the receiver candemodulate and decode the control information by using the transmissionformat of the control information, which is already recognized by thereceiver. If the control is not transmitted with a fixed format, thereceiver must try to detect the format for various possible formats byapplying a blind format detection method.

FIG. 4 illustrates the FFT mapping in the symbol block period in whichthe control information and the data are multiplexed according to thefirst exemplary embodiment of the present invention. Referring to FIG.4, the control information 400, including L modulation symbols, isapplied to the inputs of the FFT unit 404 with input indexes of 0˜(L−1),and the data is applied to the other FFT inputs, such as, the FFT inputswith the input indexes of 0˜(L−1). It should be noted that the locationsto which the modulation symbols of the control information 400 aremapped are not limited to the upper indexes of 0˜(L−1). The controlinformation may be mapped to any L number of taps known in advance tothe transmitter and the receiver from among the M input taps of the FFT′unit.

FIG. 5 illustrates a structure of a receiver according to the firstexemplary embodiment of the present invention.

Referring to FIG. 5, the receiver first eliminates the CP from thereceived signal, performs FFT by the FFT unit 502, extracts the pilotsignal from the output of the FFT unit 502, and then performs channelestimation. For example, the FFT unit 502 of the receiver converts thereceived signal input to the unit 502 to a frequency domain signal,corresponding to the IFFT unit 314 shown in FIG. 3. When the output fromthe FFT unit 502 corresponds to the pilot 510, the output of the FFTunit 502 is input to the channel estimator 504. When the symbol blockperiod in which the output of the FFT 502 occurs is a predeterminedpilot period in one TTI as shown in FIG. 3, the output of the FFT unit502 is considered as the pilot 510.

The channel estimator 504 generates channel estimation information 512by estimating the channel condition from the pilot 510 and transfers thegenerated channel estimation information 512 to the channel compensationblock 524 so that the IFFT unit 506 can demodulate the data and controlinformation. Thereafter, the output from the FFT unit 502 ischannel-compensated by using the channel estimation information 512 bythe channel compensation block 524. The extraction of the pilot 510 bythe channel estimator 504 and the channel compensation by the channelcompensation block 524 may be performed by the output side of the IFFTunit 506.

The channel-compensated signal 526 is input to the IFFT unit 506according to the IFDMA or LFDMA mapping rule applied in the transmitter,and is then subjected to the demodulation and decoding.

In the case of the symbol block period including the control informationand data, since the control information has been transmitted after beingapplied to the input indexes of 0˜(L−1) of the FFT unit 404, the IFFTunit 506 of FIG. 5 applies the outputs 520 with the output indexes of0˜(L−1) to the control information demodulator/decoder 508, so that itis possible to extract the control information. Further, in the case ofdata, since pure data may sometimes be transmitted in one symbol blockperiod, all the outputs of the IFFT unit 506, such as, the outputs 518with the output indexes of 0˜(M−1) are applied to the datademodulator/decoder 522. When the modulation and coding schemes used bythe transmitted data for data transmission, the quantity of data, theHARQ control information 516, etc. have been transferred to the datademodulator/decoder 522 by the demodulation and decoding of the controlinformation in the symbol block period corresponding to the controlinformation, the decoded data is finally output from the datademodulator/decoder 522.

FIG. 8 is a flowchart for illustrating the operation of the receiveraccording to a first exemplary embodiment of the present invention.

In step 800, the receiver eliminates the CP from the received signal,performs FFT, extracts the pilot from the FFT output, and then performschannel estimation. In step 802, when the FFT output corresponds to asymbol block period including data and control information or a symbolblock period including only data, the FFT output is channel-compensatedby the channel compensation block 524.

The signal channel-compensated in step 804 is input to the IFFT unitaccording to the IFDMA or LFDMA mapping rule applied in the transmitter.The output with an index corresponding to the control information fromamong the IFFT output corresponding to the symbol block period includingthe data and the control information is converted through demodulationand decoding to the control information including modulation and codingschemes applied to the data, HARQ control information, etc.

In step 806, the control information is used to restore data bydemodulating and decoding the IFFT output corresponding to the symbolblock period including the data and the control information or thesymbol block period including only the data.

FIG. 6 illustrates a method for multiplexing control information anddata according to a second exemplary embodiment of the presentinvention.

The second embodiment is different from the first embodiment in that thecontrol information 602 is transmitted after being distributed tomultiple symbol block periods within one TTI 600. The core of the secondexemplary embodiment of the present invention is that the controlinformation 602 is multiplexed with the data in each symbol block period604 and is transmitted after being distributed to the multiple symbolblock periods in the TTI 600, thereby obtaining time diversity in afading channel, which can improve the performance for detection of thecontrol information. Referring to FIG. 6, in the symbol block period inwhich data and control information are multiplexed, the controlinformation includes K number of symbols, data includes (M−K) number ofsymbols, and the control information and the data are applied to theinput indexes of 0˜(K−1) and K˜(M−1) of the FFT unit 610, respectively.The parameters K and M have values which are determined by the quantityof necessary control information and the quantity of data to betransmitted, respectively.

In the first exemplary embodiment of the present invention, because ofthe applied modulation and coding scheme, the number of all the symbols,the FFT input mapping, etc. in the control information 602 are definedin advance between the transmitter and the receiver, the receiver candemodulate and decode the control information based on the pre-definedtransmission format of the control information. Further, in the secondexemplary embodiment of the present invention, it is possible totransmit the pilot 606 in the fourth symbol block period within one TTI,in order to reduce the pilot overhead, in comparison with the case ofthe first exemplary embodiment of the present invention.

In the first exemplary embodiment of the present invention, thetransmission signal is mapped to the IFFT input 612 according to theIFDMA or LFDMA technique after passing through the FFT unit 610, isprocessed by the IFFT unit 614, and is then transmitted together with aCP attached thereto. The structure of the receiver for processing thetransmission signal is basically analogous to those of the firstexemplary embodiment shown in FIGS. 5 and 8. Differently from the firstembodiment, the demodulation and the decoding of the data symbols areperformed after the control information is obtained through reception,demodulation and decoding of all the symbols of the control informationdistributed in the multiple symbol block periods.

The flowcharts in FIGS. 8 and 9, according to the first exemplaryembodiment of the present invention, are applicable to the secondexemplary embodiment of the present invention.

FIG. 7 illustrates a structure for mapping of IFFT outputs to thecontrol information demodulator/decoder and the data demodulator/decoderin the receiver according to the first or second exemplary embodiment ofthe present invention.

As noted from FIG. 7, in the receiver, the outputs with indexes of0˜(K−1) and K˜(M−1) are applied to the control informationdemodulator/decoder 702 and the data demodulator/decoder 704,respectively. Each demodulator/decoder 702 or 704 can perform normaldemodulation and decoding of the control information and the data.

According to an exemplary embodiment of the present invention asdescribed above, data and control information are multiplexed in thesame symbol block and are then transmitted by a single carrier by usingan IFDMA or LFDMA scheme. Therefore, an exemplary embodiment of thepresent invention can improve the efficiency in use of resources andachieve a lower Peak-to-Average Power Ratio (PAPR), in comparison withthe existing time division or frequency division multiplexing method.

While the present invention has been shown and described with referenceto certain exemplary embodiments thereof, it will be understood by thoseskilled in the art that various changes in form and details may be madetherein without departing from the spirit and scope of the invention asdefined by the appended claims and their equivalents.

What is claimed is:
 1. A signal reception apparatus comprising: areceiver configured to receive a symbol block within a symbol periodover a wireless communication network, the symbol block only includingcontrol information and data information; and a control informationdemodulator/decoder configured for demultiplexing the controlinformation and the data information from the received symbol block. 2.The signal reception apparatus of claim 1, wherein the receiver isconfigured to receive a plurality of symbol blocks within a transmittime interval.
 3. The signal reception apparatus of claim 1, wherein thereceiver is configured to receive a signal comprising a localizedfrequency domain multiple access (LFDMA) or an interleaved frequencydomain multiple access (IFDMA) format.
 4. The signal reception apparatusof claim 3, further comprising: a Fast Fourier Transform (FFT) unitconfigured for performing an FFT on the received symbol block; anInverse Fast Fourier Transform (IFFT) unit configured for restoring thesymbol block by performing an IFFT on a first portion of a signal outputof the FFT unit.
 5. The signal reception apparatus of claim 4, furthercomprising: a channel estimator configured for generating channelestimation information by using a second portion of the signal output ofthe FFT unit; and a channel compensator configured forchannel-compensating the first portion of the signal output of the FFTunit using the generated channel estimation information.
 6. The signalreception apparatus of claim 4, wherein the IFFTed signal output furthercomprises a second portion, and further comprising: a channel estimatorconfigured for generating channel estimation information by using pilotsymbols output from a third portion of the IFFTed signal output; and achannel compensator configured for channel-compensating the firstportion of the signal output of the FFT unit using the generated channelestimation information.
 7. The signal reception apparatus of claim 4,wherein the IFFTed signal output further comprises a second portion, andfurther comprising: a channel estimator configured for generatingchannel estimation information by using pilot symbols output from athird portion of the IFFTed signal output; and a channel compensatorconfigured for channel-compensating the IFFTed signal output.
 8. Thesignal reception apparatus of claim 1, further comprising: a datademodulator/decoder configured to decode the received data informationfrom the symbol block in response to the received control informationfrom the symbol block.
 9. The signal reception apparatus of claim 1,wherein the control information comprises at least one of a modulationinformation, a channel coding information, a symbol number-relatedinformation, and an FFT mapping information.
 10. A method for receivingdata, comprising: receiving a symbol block within a symbol period over awireless communication network, the symbol block only including controlinformation and data information; and demultiplexing the controlinformation and the data information from the received symbol block. 11.The method of claim 10, wherein the step of receiving comprisesreceiving a plurality of symbol blocks within a transmit time interval.12. The method of claim 10, wherein the step of receiving comprisesreceiving a signal comprising a localized frequency domain multipleaccess (LFDMA) or an interleaved frequency domain multiple access(IFDMA) format.
 13. The method of claim 12, further comprising:performing an FFT on the received symbol block; restoring the symbolblock in the received signal by performing an IFFT on a first portion ofa signal output of the FFT unit; outputting, if the restored symbolblock comprises a control information, the control information using afirst portion of the IFFTed signal output; and outputting, if therestored symbol block comprises a data information multiplexed with thecontrol information, the data information using a second portion of theIFFTed signal output and the outputted control information.
 14. Themethod of claim 13, further comprising: generating channel estimationinformation by using the second portion of the signal output of the FFTunit; and channel-compensating the first portion of the signal output ofthe FFT unit using the generated channel estimation information.
 15. Themethod of claim 13, further comprising: generating channel estimationinformation by using pilot symbols output from a third portion of theIFFTed signal output; and channel-compensating the first portion of thesignal output of the FFT unit using the generated channel estimationinformation.
 16. The method of claim 13, further comprising: generatingchannel estimation information by using pilot symbols output from athird portion of the IFFTed signal output; and channel-compensating theIFFTed signal output.
 17. The method of claim 10, further comprising:decoding the received data information from the symbol block in responseto the received control information from the symbol block.
 18. Themethod of claim 10, wherein the control information comprises at leastone of a modulation information, a channel coding information, a symbolnumber-related information, and an FFT mapping information.
 19. Themethod of claim 10, wherein a first continuous portion of the receivedsymbol block comprises the control information and a remainingcontinuous portion of the received symbol block comprises the datainformation.
 20. A receiver apparatus comprising: means for receiving afirst symbol block within a first symbol period over a wirelesscommunication network, the symbol block only including controlinformation and data information; and means for demultiplexing thecontrol information and the data information from the received firstsymbol block.
 21. The receiver apparatus of claim 20, wherein the firstsymbol block is exclusive of pilot information.
 22. The signal receptionapparatus of claim 21, wherein the receiver is further configured toreceive a second symbol block within a second symbol period, wherein thesecond symbol block comprises the pilot information.
 23. Anon-transitory computer-readable medium embodying instructions that,when executed by a processor, allow the processor to perform a methodfor receiving data, the method comprising: receiving a symbol blockwithin a symbol period over a wireless communication network, the symbolblock only including control information and data information; anddemultiplexing the control information and the data information from thereceived symbol block.